Juliusz Chroboczek <jec@dcs.ed.ac.uk> wrote:
>
> (To clarify: I do not have any preference for one canonical order over
> the other. Just pick one and stick to it consistently.)
>
There is a good authority on which one to pick:

ISO/IEC 10646-1 : 1993 (E), Paragraph 6.3:

"The sequence of the octets that represent a character, and the most
significant and least significant ends of it, shall be maintained as shown
above [in Section 6.2, illustrating Big Endian byte organization]. When
serialised as octets, a more significant octet shall precede less significant
octets."